/* Modifications by Jungo Ltd. Copyright (c) 2012 Jungo Ltd. All Rights reserved */
/*
 * Copyright (c) 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#ifndef _UW_LISTS_H_
#define _UW_LISTS_H_

#ifndef _SYS_QUEUE_H_

/*
 * This file defines four types of data structures: singly-linked lists,
 * singly-linked tail queues, lists and tail queues.
 *
 * A singly-linked list is headed by a single forward pointer. The elements
 * are singly linked for minimum space and pointer manipulation overhead at
 * the expense of O(n) removal for arbitrary elements. New elements can be
 * added to the list after an existing element or at the head of the list.
 * Elements being removed from the head of the list should use the explicit
 * macro for this purpose for optimum efficiency. A singly-linked list may
 * only be traversed in the forward direction.  Singly-linked lists are ideal
 * for applications with large datasets and few or no removals or for
 * implementing a LIFO queue.
 *
 * A singly-linked tail queue is headed by a pair of pointers, one to the
 * head of the list and the other to the tail of the list. The elements are
 * singly linked for minimum space and pointer manipulation overhead at the
 * expense of O(n) removal for arbitrary elements. New elements can be added
 * to the list after an existing element, at the head of the list, or at the
 * end of the list. Elements being removed from the head of the tail queue
 * should use the explicit macro for this purpose for optimum efficiency.
 * A singly-linked tail queue may only be traversed in the forward direction.
 * Singly-linked tail queues are ideal for applications with large datasets
 * and few or no removals or for implementing a FIFO queue.
 *
 * A list is headed by a single forward pointer (or an array of forward
 * pointers for a hash table header). The elements are doubly linked
 * so that an arbitrary element can be removed without a need to
 * traverse the list. New elements can be added to the list before
 * or after an existing element or at the head of the list. A list
 * may only be traversed in the forward direction.
 *
 * A tail queue is headed by a pair of pointers, one to the head of the
 * list and the other to the tail of the list. The elements are doubly
 * linked so that an arbitrary element can be removed without a need to
 * traverse the list. New elements can be added to the list before or
 * after an existing element, at the head of the list, or at the end of
 * the list. A tail queue may be traversed in either direction.
 *
 * For details on the use of these macros, see the queue(3) manual page.
 *
 *
 *                      SLIST   LIST    STAILQ  TAILQ
 * _HEAD                +       +       +       +
 * _HEAD_INITIALIZER    +       +       +       +
 * _ENTRY               +       +       +       +
 * _INIT                +       +       +       +
 * _EMPTY               +       +       +       +
 * _FIRST               +       +       +       +
 * _NEXT                +       +       +       +
 * _PREV                -       -       -       +
 * _LAST                -       -       +       +
 * _FOREACH             +       +       +       +
 * _FOREACH_REVERSE     -       -       -       +
 * _INSERT_HEAD         +       +       +       +
 * _INSERT_BEFORE       -       +       -       +
 * _INSERT_AFTER        +       +       +       +
 * _INSERT_TAIL         -       -       +       +
 * _REMOVE_HEAD         +       -       +       -
 * _REMOVE              -       +       -       +
 * _MOVE_HEAD           -       -       +       -
 *
 */

#define TAILQ_ENTRY(type)                                              \
    struct                                                             \
    {                                                                  \
        struct type *tqe_next;  /* next element */                     \
        struct type **tqe_prev; /* address of previous next element */ \
    }

#define TAILQ_HEAD(name, type)                                  \
    struct name                                                 \
    {                                                           \
        struct type *tqh_first; /* first element */             \
        struct type **tqh_last; /* addr of last next element */ \
    }

#define TAILQ_EMPTY(head) ((head)->tqh_first == NULL)

#define TAILQ_FIRST(head) ((head)->tqh_first)

#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)

#define TAILQ_PREV(elm, headname, field) \
    (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))

#define TAILQ_REMOVE(head, elm, field)                     \
    do                                                     \
    {                                                      \
        if ((TAILQ_NEXT((elm), field)) != NULL)            \
        {                                                  \
            TAILQ_NEXT((elm), field)->field.tqe_prev =     \
                (elm)->field.tqe_prev;                     \
        }                                                  \
        else                                               \
        {                                                  \
            (head)->tqh_last = (elm)->field.tqe_prev;      \
        }                                                  \
        *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \
    } while (0)

#define TAILQ_REMOVE_HEAD(head, field)                \
    do                                                \
    {                                                 \
        TAILQ_REMOVE(head, TAILQ_FIRST(head), field); \
    } while (0)

#define TAILQ_FIND(list, item, type, next, found) \
    do                                            \
    {                                             \
        type curr_tf;                             \
        type next_tf;                             \
                                                  \
        curr_tf = TAILQ_FIRST((list));            \
        while (curr_tf)                           \
        {                                         \
            next_tf = TAILQ_NEXT(curr_tf, next);  \
            if (curr_tf == (item))                \
            {                                     \
                found = 1;                        \
                break;                            \
            }                                     \
            curr_tf = next_tf;                    \
        }                                         \
    } while (0)

#define TAILQ_FIND_AND_REMOVE(list, item, type, next, removed) \
    do                                                         \
    {                                                          \
        type curr_tf;                                          \
        type next_tf;                                          \
                                                               \
        removed = 0;                                           \
        curr_tf = TAILQ_FIRST((list));                         \
        while (curr_tf)                                        \
        {                                                      \
            next_tf = TAILQ_NEXT(curr_tf, next);               \
            if (curr_tf == (item))                             \
            {                                                  \
                TAILQ_REMOVE((list), curr_tf, next);           \
                removed = 1;                                   \
                UNUSED_VAR(removed);                           \
            }                                                  \
            curr_tf = next_tf;                                 \
        }                                                      \
    } while (0)

#define TAILQ_INSERT_TAIL(head, elm, field)           \
    do                                                \
    {                                                 \
        TAILQ_NEXT((elm), field) = NULL;              \
        (elm)->field.tqe_prev = (head)->tqh_last;     \
        *(head)->tqh_last = (elm);                    \
        (head)->tqh_last = &TAILQ_NEXT((elm), field); \
    } while (0)

#define TAILQ_INSERT_HEAD(head, elm, field)                                  \
    do                                                                       \
    {                                                                        \
        if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL)        \
        {                                                                    \
            TAILQ_FIRST((head))->field.tqe_prev = &TAILQ_NEXT((elm), field); \
        }                                                                    \
        else                                                                 \
        {                                                                    \
            (head)->tqh_last = &TAILQ_NEXT((elm), field);                    \
        }                                                                    \
        TAILQ_FIRST((head)) = (elm);                                         \
        (elm)->field.tqe_prev = &TAILQ_FIRST((head));                        \
    } while (0)

#define TAILQ_HEAD_INITIALIZER(head) \
    {                                \
        NULL, &(head).tqh_first      \
    }

#define TAILQ_INIT(head)                         \
    do                                           \
    {                                            \
        TAILQ_FIRST((head)) = NULL;              \
        (head)->tqh_last = &TAILQ_FIRST((head)); \
    } while (0)

#define TAILQ_INSERT_AFTER(head, listelm, elm, field)                          \
    do                                                                         \
    {                                                                          \
        if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL) \
        {                                                                      \
            TAILQ_NEXT((elm), field)->field.tqe_prev = &TAILQ_NEXT((elm),      \
                                                                   field);     \
        }                                                                      \
        else                                                                   \
        {                                                                      \
            (head)->tqh_last = &TAILQ_NEXT((elm), field);                      \
        }                                                                      \
        TAILQ_NEXT((listelm), field) = (elm);                                  \
        (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field);                 \
    } while (0)

#define TAILQ_INSERT_BEFORE(listelm, elm, field)               \
    do                                                         \
    {                                                          \
        (elm)->field.tqe_prev = (listelm)->field.tqe_prev;     \
        TAILQ_NEXT((elm), field) = (listelm);                  \
        *(listelm)->field.tqe_prev = (elm);                    \
        (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \
    } while (0)

#define TAILQ_LAST(head, headname) \
    (*(((struct headname *)((head)->tqh_last))->tqh_last))

#define TAILQ_FOREACH(var, head, field) \
    for ((var) = TAILQ_FIRST((head));   \
         (var);                         \
         (var) = TAILQ_NEXT((var), field))

#define TAILQ_FOREACH_SAFE(var, head, field, tvar)        \
    for ((var) = TAILQ_FIRST((head));                     \
         (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \
         (var) = (tvar))

#define TAILQ_FOREACH_REVERSE(var, head, headname, field) \
    for ((var) = TAILQ_LAST((head), headname);            \
         (var);                                           \
         (var) = TAILQ_PREV((var), headname, field))

/*
 * Singly-linked Tail queue declarations.
 */
#define STAILQ_HEAD(name, type)                                  \
    struct name                                                  \
    {                                                            \
        struct type *stqh_first; /* first element */             \
        struct type **stqh_last; /* addr of last next element */ \
    }

#define STAILQ_ENTRY(type)                         \
    struct                                         \
    {                                              \
        struct type *stqe_next; /* next element */ \
    }

/*
 * Singly-linked Tail access methods
 */
#define STAILQ_EMPTY(head) ((head)->stqh_first == NULL)
#define STAILQ_FIRST(head) ((head)->stqh_first)
#define STAILQ_LAST(head, type, field) \
    (STAILQ_EMPTY((head)) ? NULL : ((type *)(void *)((char *)((head)->stqh_last) - ((char *)&(((type *)0)->field)))))

#define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)

/*
 * Singly-linked Tail queue functions
 */
#define STAILQ_REMOVE_HEAD(head, field)                             \
    do                                                              \
    {                                                               \
        if ((STAILQ_FIRST((head)) =                                 \
                 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \
            (head)->stqh_last = &STAILQ_FIRST((head));              \
    } while (0)

#define STAILQ_INSERT_HEAD(head, elm, field)                            \
    do                                                                  \
    {                                                                   \
        if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \
            (head)->stqh_last = &STAILQ_NEXT((elm), field);             \
        STAILQ_FIRST((head)) = (elm);                                   \
    } while (0)

#define STAILQ_MOVE_HEAD(head_src, head_dst)                 \
    do                                                       \
    {                                                        \
        if (STAILQ_FIRST(head_src))                          \
        {                                                    \
            (head_dst)->stqh_first = (head_src)->stqh_first; \
            (head_dst)->stqh_last = (head_src)->stqh_last;   \
            STAILQ_INIT(head_src);                           \
        }                                                    \
        else                                                 \
        {                                                    \
            STAILQ_INIT(head_dst);                           \
        }                                                    \
    } while (0)

#define STAILQ_INSERT_TAIL(head, elm, field)            \
    do                                                  \
    {                                                   \
        STAILQ_NEXT((elm), field) = NULL;               \
        *(head)->stqh_last = (elm);                     \
        (head)->stqh_last = &STAILQ_NEXT((elm), field); \
    } while (0)

#define STAILQ_FOREACH(var, head, field) \
    for ((var) = STAILQ_FIRST((head));   \
         (var);                          \
         (var) = STAILQ_NEXT((var), field))

#define STAILQ_INIT(head)                          \
    do                                             \
    {                                              \
        STAILQ_FIRST((head)) = NULL;               \
        (head)->stqh_last = &STAILQ_FIRST((head)); \
    } while (0)

/*
 * List definitions.
 */
#ifdef LIST_HEAD
#undef LIST_HEAD
#endif
#define LIST_HEAD(name, type)                      \
    struct name                                    \
    {                                              \
        struct type *lh_first; /* first element */ \
    }

#define LIST_ENTRY(type)                                              \
    struct                                                            \
    {                                                                 \
        struct type *le_next;  /* next element */                     \
        struct type **le_prev; /* address of previous next element */ \
    }

/*
 * List access methods.
 */
#define LIST_EMPTY(head) ((head)->lh_first == NULL)
#define LIST_FIRST(head) ((head)->lh_first)
#define LIST_NEXT(elm, field) ((elm)->field.le_next)

/*
 * List functions.
 */
#define LIST_HEAD_INITIALIZER(head) \
    {                               \
        NULL                        \
    }

#define LIST_INIT(head)            \
    do                             \
    {                              \
        LIST_FIRST((head)) = NULL; \
    } while (0)

#define LIST_FOREACH(var, head, field) \
    for ((var) = LIST_FIRST((head));   \
         (var);                        \
         (var) = LIST_NEXT((var), field))

#define LIST_FOREACH_SAFE(var, head, field, tvar)        \
    for ((var) = LIST_FIRST((head));                     \
         (var) && ((tvar) = LIST_NEXT((var), field), 1); \
         (var) = (tvar))

#define LIST_INSERT_AFTER(listelm, elm, field)                               \
    do                                                                       \
    {                                                                        \
        if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL) \
        {                                                                    \
            LIST_NEXT((listelm), field)->field.le_prev =                     \
                &LIST_NEXT((elm), field);                                    \
        }                                                                    \
        LIST_NEXT((listelm), field) = (elm);                                 \
        (elm)->field.le_prev = &LIST_NEXT((listelm), field);                 \
    } while (0)

#define LIST_INSERT_BEFORE(listelm, elm, field)              \
    do                                                       \
    {                                                        \
        (elm)->field.le_prev = (listelm)->field.le_prev;     \
        LIST_NEXT((elm), field) = (listelm);                 \
        *(listelm)->field.le_prev = (elm);                   \
        (listelm)->field.le_prev = &LIST_NEXT((elm), field); \
    } while (0)

#define LIST_INSERT_HEAD(head, elm, field)                                \
    do                                                                    \
    {                                                                     \
        if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL)       \
            LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field); \
        LIST_FIRST((head)) = (elm);                                       \
        (elm)->field.le_prev = &LIST_FIRST((head));                       \
    } while (0)

#define LIST_REMOVE(elm, field)                          \
    do                                                   \
    {                                                    \
        if (LIST_NEXT((elm), field) != NULL)             \
        {                                                \
            LIST_NEXT((elm), field)->field.le_prev =     \
                (elm)->field.le_prev;                    \
        }                                                \
        *(elm)->field.le_prev = LIST_NEXT((elm), field); \
    } while (0)

/*
 * Singly-linked List definitions.
 */
#define SLIST_HEAD(name, type)                      \
    struct name                                     \
    {                                               \
        struct type *slh_first; /* first element */ \
    }

#define SLIST_HEAD_INITIALIZER(head) \
    {                                \
        NULL                         \
    }

#define SLIST_ENTRY(type)                         \
    struct                                        \
    {                                             \
        struct type *sle_next; /* next element */ \
    }

/*
 * Singly-linked List functions.
 */
#define SLIST_INIT(head)          \
    do                            \
    {                             \
        (head)->slh_first = NULL; \
    } while (0)

#define SLIST_INSERT_AFTER(slistelm, elm, field)            \
    do                                                      \
    {                                                       \
        (elm)->field.sle_next = (slistelm)->field.sle_next; \
        (slistelm)->field.sle_next = (elm);                 \
    } while (0)

#define SLIST_INSERT_HEAD(head, elm, field)        \
    do                                             \
    {                                              \
        (elm)->field.sle_next = (head)->slh_first; \
        (head)->slh_first = (elm);                 \
    } while (0)

#define SLIST_REMOVE_HEAD(head, field)                         \
    do                                                         \
    {                                                          \
        (head)->slh_first = (head)->slh_first->field.sle_next; \
    } while (0)

#define SLIST_REMOVE_AFTER(slistelm, field)                   \
    do                                                        \
    {                                                         \
        (slistelm)->field.sle_next =                          \
            SLIST_NEXT(SLIST_NEXT((slistelm), field), field); \
    } while (0)

#define SLIST_FOREACH(var, head, field) \
    for ((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next)

/*
 * Singly-linked List access methods.
 */
#define SLIST_EMPTY(head) ((head)->slh_first == NULL)
#define SLIST_FIRST(head) ((head)->slh_first)
#define SLIST_NEXT(elm, field) ((elm)->field.sle_next)

#endif
#endif
